For the Fallen

30

Recover all of the COG tags (on any difficulty)

COG tags are the future's equivalent of dogtags. They are hidden throughout the game and can be picked up in various chapters of every act. You will notice them by their illuminated blue glow. If you have picked up a COG tag in a certain area, and are playing through the game again, you will not be able to pick that COG tag up again. The number of COGs you have picked up can be seen in the pause menu.